Solar power collectors

ABSTRACT

The present invention provides a solar power collector for harnessing the thermal energy of the sun, comprising: a collection system comprising a cone shaped to reflect sunlight to a target where a circulating working fluid absorbs the thermal energy such that the working fluid is heated; a base including a controller and motors to rotate the collection system to track the sun throughout the day; and a conversion system for receiving the heated working fluid, transferring the heat, and returning a cooled working fluid.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This technical disclosure generally relates to concentrating solar energy to generate electricity or to heat and cool fluids and, more particularly, to concentrating solar energy using one or more materials to form a collector cone.

2. Description of the Invention

Increasing oil prices and environmental concerns have recently highlighted the desire to decrease the dependence on fossil fuels. This desire has stimulated research into clean and renewable ways to produce electricity for the global marketplace. Solar power is a viable option because it is a clean form of energy with an unlimited supply. Technological innovations and improvements are constantly reducing the costs associated with installing, operating, and maintaining solar power equipment. Furthermore, conversion efficiencies have dramatically increased over the years, thereby reducing the size of the equipment necessary to harness the thermal energy produced by the sun.

Focusing solar energy to high intensity can provide high temperatures at the target (focal point) in order to drive high-efficiency heat engines. Parabolic trough reflectors have been used effectively in this role, while parabolic dish mirrors can achieve even higher temperatures. However, with parabolic trough and dish mirrors, considerable precision is required to construct and maintain them. The mirror facets of a parabolic dish concentrator are fairly expensive to manufacture. Each facet must be mounted on a very rigid structure and must be precisely aligned to keep the sun's image on the target. About once a week, each mirror must be realigned. For a 100 square meter dish (1 m² per facet), 100 mirrors must be realigned. Realignment can be done by electronically-controlled actuators, but that requires two motors per mirror facet in addition to sophisticated electronics.

Parabolic dish reflectors have been known to start fires in grass when accidentally pointed in the wrong direction. They can also cause damage to human eyes if the mirror points in a direction that causes sunlight reflection toward a person or if the person looks at the target (focal point).

SUMMARY OF THE INVENTION

Solar power collectors described herein can be used to focus solar energy and provide high temperatures at the target (focal point). These high temperatures can then be used to heat a circulating fluid or to drive an engine to generate electricity, thereby offsetting conventional energy usage in a house or commercial building. The solar power collectors are relatively simple to construct and less costly than prior art devices, and do not require highly skilled users to utilize or maintain their use.

According to some embodiments, a solar power collector for harnessing the thermal energy of the sun includes a collection system, a base and a conversion system. The base includes a controller and motors to rotate the collection system to track the sun throughout the day. The collection system comprises a cone shaped to reflect sunlight to a target where a circulating working fluid absorbs the thermal energy. The conversion system then takes the heated working fluid, transfers the heat to the ambient air or domestic hot water in a home and then returns a cooled working fluid.

In a further embodiment, a solar power collector for harnessing the thermal energy of the sun includes a collection system, a base and a conversion system. The base includes a controller and motors to rotate the collection system to track the sun throughout the day. The collection system comprises a broken cone design similar to a Fresnel reflector. The broken cone comprises a plurality of plates shaped to reflect sunlight to a target. The thermal energy is concentrated on the target which is then transferred to the conversion system. The conversion system comprises a heat engine, such as, for example, a Stirling engine. The conversion system converts the thermal energy from the collection system into electricity which can then be utilized in a building or sold onto the power grid.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the nature and desired objects of the solar power collectors, reference is made to the following detailed description taken in conjunction with the accompanying drawing figures wherein like reference characters denote corresponding parts throughout the several views and wherein:

FIG. 1 is a perspective view of a single cone design according to an exemplary embodiment of a solar power collector;

FIG. 2 is a front-view schematic of the embodiment shown in FIG. 1;

FIG. 3 is a cross-sectional side-view of the embodiment shown in FIG. 2 taken along the line A-A;

FIG. 4A is side-view schematic of the embodiment shown in FIG. 1;

FIG. 4B is a schematic view of the embodiment shown in FIG. 4A taken along the line B-B;

FIG. 5 is top-view schematic of the embodiment shown in FIG. 1;

FIG. 6 is back-view schematic of the embodiment shown in FIG. 1;

FIG. 7 is a schematic view of a system for extracting thermal energy from a working fluid according to an exemplary embodiment of a conversion system;

FIG. 8 is a schematic view of a salt water distillation system according to an exemplary embodiment of a conversion system;

FIG. 9 is a perspective view of a multi-cone design according to another embodiment of a solar power collector;

FIG. 10 is a front-view schematic of the embodiment shown in FIG. 7;

FIG. 11 is a cross-sectional side-view of the embodiment shown in FIG. 8 taken along the line C-C;

FIG. 12A is side-view schematic of the embodiment shown in FIG. 7;

FIG. 12B is a schematic view of the embodiment shown in FIG. 10A taken along the line B′-B′;

FIG. 13 is top-view schematic of the embodiment shown in FIG. 7;

FIG. 14 is back-view schematic of the embodiment shown in FIG. 7;

FIG. 15 is a schematic side-view of the embodiment shown in FIG. 7 showing the rays of the sun reflecting onto the target; and

FIG. 16 is a schematic view of a Stirling engine according to an exemplary embodiment of a conversion system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to FIGS. 1-8, one exemplary embodiment of a solar power collector 10 is illustrated. The solar power collector 10 includes a collection system 12 that focuses sunlight to a target 14. The target 14 is coupled to a conversion system 16 that converts the thermal energy from the sun to energy that can be used in place of, or in conjunction with conventional energy sources. It is envisioned that the solar power collector 10 finds may be employed in applications such as the heating or cooling of ambient air in a building, heating water (e.g., for domestic use), and distilling salt water into fresh water.

The collection system 12 includes a cone 18 dimensioned to focus the reflected sunlight to the target 14. It is envisioned that the cone 18 can be fabricated in one piece or in multiple sections. The multiple sections are then assembled and held together with mechanical fasteners, heat or ultrasonic welding, adhesives, or by other means or techniques known to those skilled in the art. A multiple section cone 18 may provide simpler and more flexible methods of manufacturing. In this embodiment, the cone 18 is formed by two sections 20, 22. The cone 18 has a vertex 24, an interior surface 26, an exterior surface 28, and a circular opening 30 that is pointed toward the sun. A Mylar® film is disposed on the interior surface 26 of the cone 18 and can periodically be replaced when necessary.

The cone 18 is coupled to a frame 32 to support the cone 18. The frame 32 includes a base disk 34 at the vertex 24 of the cone 18 and three frame rods 36, 38, 40 extending from the base disk 34 along the exterior surface 28 to a wash ring 42, which surrounds the circular opening 30. The wash ring 42 has a plurality of openings or nozzles from which a cleaning solution or surfactant can be sprayed onto the interior surface 26 to clean the Mylar® film. The frame 32 may include more or fewer components depending on the size, weight, and desired application of the solar power collector 10.

The frame 32 is movably connected to a base 44. The base 44 may be positioned on the ground or on the roof of a building. The movable connection 46 provides one axis of rotation in the vertical direction so as to allow the vertical elevation of the cone 18 to be adjusted from a horizontal position to a vertical position pointing straight up into the sky. Also, to provide a second axis of rotation in the horizontal direction, the cone 18 can rotate 360 degrees with respect to the base 44 to provide total tracking of the sun. A controller coupled to the collection system 12 drives two independent motors 48 that adjust the elevation and azimuth direction of the collection system 12 to track the sun across the sky.

The thermal energy from the collection system 12 is transferred to the target 14. In this embodiment the target 14 is a rod 50 filled with a working fluid. The cone 18 having two sections 20, 22 is designed to reduce the length of rod 50, thereby increasing thermal efficiency and reducing the likelihood of air gaps in the working fluid liquid. The working fluid may be any number of heat transfer fluids know in the art such as, water, ethylene glycol or oil.

The conversion system 16 transfers the heated working fluid away from the target 14 and converts the thermal energy to other usable forms of energy. The conversion system 16 generally includes a heat exchanger, and means for circulating working fluid from the target 14 to the heat exchanger and then back to the target 14 in a closed loop. In the simplest embodiment, the means for circulating the fluid is a conduit, but may also include pumps, temperature and pressure monitoring devices, valves, and flow controlling units.

The conversion system 16 may also include a salt water distillation system (FIG. 8). The heated working fluid is circulated through a salt water steam chamber to vaporize the water. A second cooled working fluid is circulated thought a distillation plate to increase the temperature differential, thereby increasing the distillation rate. The vaporized water molecules condense creating fresh water.

In operation, sunlight shines on the interior surface 26 of the cone 18, which concentrates the thermal energy onto the rod 50. The target 14 is made from a conductive material, such as, for example, nickel, aluminum or copper. The rod 50 absorbs the thermal energy and transfers it to the working fluid. The conversion system 16 circulates the heated working fluid, extracts the thermal energy and returns the cooled working fluid back to the rod in a closed loop system. As the sun moves across the sky during the day, the controller drives the motors 48 to constantly adjust the elevation and azimuth direction of the collection system 12 to maximize the thermal energy being collected by the solar power collector 10.

In some embodiments, the solar power system 10 can be used at nighttime to cool the working fluid. At night, the cone 18 is simply pointed toward clear sky. As the working fluid is cooled, the conversion system 16 circulates the cooled fluid which is used for circulation. In order to maximize the efficiency of each of the heating and cooling cycles, two independent working fluids are generally used and can be stored in two separate tanks or utilized in two independent circulating systems. This cooled working fluid can be used to cool the distillation plate of the salt water distillation system described above.

Turning to FIGS. 9-16, there is shown a second exemplary embodiment of a solar power collector 110. The solar power collector 110 is similar to the solar power collector 10 described above, and therefore like reference numerals preceded by the numeral “1” are used to indicate like elements. The solar power collector 110 includes a collection system 112 that focuses sunlight to a target 114. The target 114 includes a conversion system 116 that converts the thermal energy from the sun to energy that can be used in place of, or in conjunction with conventional energy sources.

The collection system 112 includes a broken cone 118 comprising a plurality of plates 119 shaped to focus the reflected sunlight to the target 114. This broken cone 118 design is based on the same scientific principals as a Fresnel lens and is sometimes referred to as a Fresnel reflector. A description of Fresnel lenses and how they work can be found at http://en.wikipedia.org/wiki/Fresnel_lens. As shown, the broken cone 118 design has eight plates 119, but could have more or fewer depending on the desired size and/or application of the solar power collector 110. Each plate 119 has an interior surface 126, an exterior surface 128, and a circular opening 130 that is pointed toward the sun. A Mylar® film is disposed on the interior surface 126 of each plate 119 and can periodically be replaced when necessary.

The plurality of plates 119 are coupled to a frame 132 to support the plates 119 and form the broken cone shape. The frame 132 is movably connected to a base 144. The base 144 may be positioned on the ground or on the roof of a building. The base 144 includes a controller and two independent motors 148 and operates in the same manner as the base 44 discussed above to provide two axes of rotation. The two axes of rotation allow adjustment of the elevation and azimuth direction of the collection system 112 to track the sun across the sky.

As shown in FIG. 15, sunlight shines on the interior surface 126 of the plates 119. The thermal energy is then transferred to the target 114. The target 114 transmits the thermal energy to the conversion system 116. In this embodiment, the conversion system 116 includes an engine 160 (FIG. 16) that converts the thermal energy into electricity. A cooling coil may optionally be included to cool the engine 160 thereby increase its conversion efficiency. The engine 160 can be any type of engine including, for example, a free-piston Stirling engine, kinematic Stirling engine, Brayton cycle engine, or steam turbine. The thermal energy from the target 114 drives the engine 160 to create an alternating current (AC) output as known in the art. An electrical connection carries the AC output to a building or to the power grid in a conventional manner.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of ordinary skill in the art to which this invention belongs. All patents, applications, published applications and other publications referred to herein are incorporated by reference in their entirety. If a definition set forth in this section is contrary to or otherwise inconsistent with a definition set forth in applications, published applications and other publications that are herein incorporated by reference, the definition set forth in this section prevails over the definition that is incorporated herein by reference.

While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not of limitation. Likewise, the various diagrams may depict an example architectural or other configuration for the invention, which is done to aid in understanding the features and functionality that can be included in the invention. The invention is not restricted to the illustrated example architectures or configurations, but the desired features can be implemented using a variety of alternative architectures and configurations. Indeed, it will be apparent to one of skill in the art how alternative functional, logical or physical partitioning and configurations can be implemented to implement the desired features of the present invention. Also, a multitude of different constituent module names other than those depicted herein can be applied to the various partitions. Additionally, with regard to flow diagrams, operational descriptions and method claims, the order in which the steps are presented herein shall not mandate that various embodiments be implemented to perform the recited functionality in the same order unless the context dictates otherwise.

Although the invention is described above in terms of various exemplary embodiments and implementations, it should be understood that the various features, aspects and functionality described in one or more of the individual embodiments are not limited in their applicability to the particular embodiment with which they are described, but instead can be applied, alone or in various combinations, to one or more of the other embodiments of the invention, whether or not such embodiments are described and whether or not such features are presented as being a part of a described embodiment. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments.

Terms and phrases used in this document, and variations thereof, unless otherwise expressly stated, should be construed as open ended as opposed to limiting. As examples of the foregoing: the term “including” should be read as meaning “including, without limitation” or the like; the term “example” is used to provide exemplary instances of the item in discussion, not an exhaustive or limiting list thereof; the terms “a” or “an” should be read as meaning “at least one,” “one or more” or the like; and adjectives such as “conventional,” “traditional,” “normal,” “standard,” “known” and terms of similar meaning should not be construed as limiting the item described to a given time period or to an item available as of a given time, but instead should be read to encompass conventional, traditional, normal, or standard technologies that may be available or known now or at any time in the future. Likewise, where this document refers to technologies that would be apparent or known to one of ordinary skill in the art, such technologies encompass those apparent or known to the skilled artisan now or at any time in the future.

A group of items linked with the conjunction “and” should not be read as requiring that each and every one of those items be present in the grouping, but rather should be read as “and/or” unless expressly stated otherwise. Similarly, a group of items linked with the conjunction “or” should not be read as requiring mutual exclusivity among that group, but rather should also be read as “and/or” unless expressly stated otherwise. Furthermore, although items, elements or components of the invention may be described or claimed in the singular, the plural is contemplated to be within the scope thereof unless limitation to the singular is explicitly stated.

The presence of broadening words and phrases such as “one or more,” “at least,” “but not limited to” or other like phrases in some instances shall not be read to mean that the narrower case is intended or required in instances where such broadening phrases may be absent. The use of the term “module” does not imply that the components or functionality described or claimed as part of the module are all configured in a common package. Indeed, any or all of the various components of a module, whether control logic or other components, can be combined in a single package or separately maintained and can further be distributed in multiple groupings or packages or across multiple locations.

Additionally, the various embodiments set forth herein are described in terms of exemplary block diagrams, flow charts and other illustrations. As will become apparent to one of ordinary skill in the art after reading this document, the illustrated embodiments and their various alternatives can be implemented without confinement to the illustrated examples. For example, block diagrams and their accompanying description should not be construed as mandating a particular architecture or configuration. 

1. A solar power collector for harnessing the thermal energy of the sun, comprising: a collection system comprising a cone shaped to reflect sunlight to a target where a circulating working fluid absorbs the thermal energy such that the working fluid is heated; a base including a controller and motors to rotate the collection system to track the sun throughout the day; and a conversion system for receiving the heated working fluid, transferring the heat, and returning a cooled working fluid.
 2. The solar power collector of claim 1, wherein the heat is transferred to the ambient air within an enclosure.
 3. The solar power collector of claim 1, wherein the heat is transferred to a source of water.
 4. The solar power collector of claim 1, wherein the cone comprises a multiple section cone.
 5. The solar power collector of claim 1, wherein the cone comprises a vertex, an interior surface, an exterior surface, and a circular opening that is pointed toward the sun.
 6. The solar power collector of claim 5, wherein the cone further comprises wash ring that surrounds the circular opening, the wash ring including a plurality of openings from which a cleaning solution is sprayed onto the interior surface of the cone.
 7. The solar power collector of claim 1, wherein the cone is connected to the base by way of a movable connection that provides one axis of rotation in the vertical direction so as to allow the vertical elevation of the cone to be adjusted, and a second axis of rotation in the horizontal direction to allow the cone to rotate 360 degrees with respect to the base.
 8. The solar power collector of claim 7, wherein as the sun moves across the sky during the day, a controller drives one or more motors to constantly adjust the elevation and azimuth direction of the collection system to maximize the thermal energy being collected by the solar power collector.
 9. The solar power collector of claim 1, wherein the conversion system further comprises a salt water distillation system, wherein the heated working fluid is circulated through a salt water steam chamber to vaporize the water, such that the water molecules condense creating fresh water.
 10. The solar power collector of claim 8, wherein a second cooled working fluid is circulated thought a distillation plate to increase the temperature differential, thereby increasing the distillation rate.
 11. A solar power collector for harnessing the thermal energy of the sun, comprising: a collection system comprising a broken cone having a plurality of plates shaped to reflect the sun's thermal energy to a target, which is then transferred to a conversion system; a base including a controller and motors to rotate the collection system to track the sun throughout the day; and a conversion system comprising a heat engine for converting the thermal energy from the collection system into electricity.
 12. The solar power collector of claim 11, wherein the broken cone comprises a Fresnel reflector.
 13. The solar power collector of claim 11, wherein the heat engine comprises a Stirling engine.
 14. The solar power collector of claim 11, wherein the heat is transferred to the ambient air within an enclosure.
 15. The solar power collector of claim 11, wherein the heat is transferred to a source of water.
 16. The solar power collector of claim 11, wherein the cone is connected to the base by way of a movable connection that provides one axis of rotation in the vertical direction so as to allow the vertical elevation of the cone to be adjusted, and a second axis of rotation in the horizontal direction to allow the cone to rotate 360 degrees with respect to the base.
 17. The solar power collector of claim 16, wherein as the sun moves across the sky during the day, a controller drives one or more motors to constantly adjust the elevation and azimuth direction of the collection system to maximize the thermal energy being collected by the solar power collector.
 18. The solar power collector of claim 11, wherein the conversion system further comprises a salt water distillation system, wherein the heated working fluid is circulated through a salt water steam chamber to vaporize the water, such that the water molecules condense creating fresh water.
 19. The solar power collector of claim 8, wherein a second cooled working fluid is circulated thought a distillation plate to increase the temperature differential, thereby increasing the distillation rate.
 20. The solar power collector of claim 11, wherein the broken cone comprises a plurality of plates shaped to focus the reflected sunlight to the target. 